Heres the easy way to look at it
The president can send troops where ever he wants, hes the commander in chief of the armed services, he has that authority.
That's a pretty radical interpretation of the constitution.
I cut out the last part because I didn't think it was all that relevant to what you said in the first part. Irrespective of whether congress has the power of the purse, it's pretty radical to suggest that the president is empowered, by the constitution, to send troops "wherever he wants". Maybe I'm just behind the times though
When was the last time we had a declaration of war?
Does it drive you crazy that the President can send troops to defend the nation? I feel your pain,it's similiar to the Supreme Court making law rather than interpeting.just by fiat.